Shifting cultivation and grazing practices have been blamed for much of the watershed degradation occurring in developing countries, particularly in mountainous regions. Increasing population pressures are considered the underlying reason why such practices are now causing problems. In the case of shifting cultivation, only 10 to 15% of the land may be cultivated at any point in time; however, population pressures compel shifting cultivators to reduce fallow periods to speed up the rotation cycle. This leads to a depletion of organic matter, soil erosion and lower long-term productivity. Likewise, increasing populations of humans -- all raising more livestock, plus the absence of land ownership, no control over movements of people and animals, and in general very little sense of land husbandry, all lead to overgrazing.
This session focused on the above problems; specific points made by individual authors include:
Chanpbaka and Nair both stated that shifting cultivation is an important land use in many countries and cannot be simply eliminated. Nair reports that shifting cultivation is practiced on 30% of the world's exploitable soils (360 million ha) and supports 8% (250 million people) of the world's population. Shifting cultivation is a valid system of land use which is not necessarily detrimental to watershed management -- provided there is an adequate fallow period to replenish organic matter and restore soil productivity.
Chanphaka emphasized that the welfare of the shifting cultivators must be a major consideration in any upland watershed management program. An integrated approach is needed to fully accommodate the socio-economic factors while attempting to improve the biological and physical condition of watersheds. Resettlement programs may be needed in some instances, but in all cases the key is to find ways to increase production without negatively affecting the environment.
Nair suggests that agroforestry practices offer viable land use alternatives to detrimental shifting cultivation practices and also to large-scale reforestation. Agroforestry can mitigate certain land management problems in a variety of climates. Examples of agrosilvicultural, silvopastoral and agrosilvopastoral systems are given. Nair emphasizes that many of these are traditional land use practices in different parts of the world and are, therefore, readily accepted by local farmers. The advantage of agroforestry over largescale forest plantations is that food, as well as wood, are produced in a sustainable manner. There is presently a need to develop research capability and develop appropriate plant combinations that achieve the objectives of producing food, various wood products and watershed protection from the perspective of the whole system.
Sheikh discussed problems of overgrazing in the developing world and stressed, again, the importance of considering man and his needs in any watershed management activity. The best laid plans of watershed managers may go astray by exogenous forces such as an influx of refugees with animals in critical ecological zones, mountain pastures, or even croplands. Examples of grazing problems are presented to highlight the biophysical effects and the socioeconomic considerations. Innovative solutions are needed in the arena of communal grazing lands or public grazing lands. Particularly with public lands, there is a tendency for the "tragedy of the commons" to prevail. Community ownership and management may be desirable over "free access" of public lands.
During the discussion, further points were made, including:
The instability of land tenure and the complexity of user rights seriously constrain the development of land use practices needed to stabilize forests and rangelands. These constraints must be overcome before watershed management programmes can become effective.
Population pressures and the push for cash cropping, rather than subsistence farming, are de-stabilizing traditional shifting agriculture in some parts of the world. People are staying too long in sensitive areas and are depleting soil nutrients and initiating surface and gully erosion.
The introduction of appropriate woody perennials through agroforestry systems, with the correct spacing and timing, can stabilize some of the present cropping systems, both economically and ecologically.
An institutional niche needs to be developed for agroforestry. Organizations like ICRAF can help catalyze research in different countries, but there is a need for hard data to support agroforestry as an acceptable land use approach to commodity oriented cropping (and institutions). Outputs from agroforestry systems, e.g., fuelwood, fodder, food, and regulated and high quality water, must be quantified.
Grazing control including fodder production on steep slopes and stall feeding or tethering of animals provides a viable alternative to present grazing practices. Steep slopes can be protected to allow soil and vegetation to recover, animal production is sustained, and the concentration of manure allows for a more controlled crop management and reduced fertilizer costs.
